Rotary pump and the like



Feb. 12, 1929.

A. L. FULLERTQN ROTARY PUMP AND THE LIKE Filed Nov. 12, 1927 3 Sheets-Sheet 1 Arum/v C.

Feb. 12, 1929.

A. L. FULLERTON ROTARY PUMP AND THE LIKE Filed Nov. 12, 1927 3 Sheets-Sheet 2 Feb. 12, 1929.

1,702,046 A. L. FULLERTON ROTARY PUMP AND THE LIKE I Filed Nov. 12, 1927 3 Sheets-Sheet 3 Mwm y y Patented Feb. 12, 1929.

NlTED STATES.

PATENT OFFICE.

ROTARY rmvne an]: THE LIKE.

"Application filed November 12, 1927. Serial No. 232,812.

The invention has relation to organizations of the class of which the well-known gear pumps are typical, such organizations being employed usually as rotary pumps but also to some extent as rotary motors.

The invention has for its main object the production of an improved organization of the class aforesaid, embodying improvements producing an improved pump or it), motor and securing certain desirable results in operation. One of the special objects is to provide for securing, in the case of a rotary pump, a high rate of flow, and con tinuity and uniformity in the load uponthe Ma rotor shafts, with a minimum of vibration. Another is to secure a surface-seal efiect which shall reduce and practically eliminate leakage from the discharge side of the rotors back to the suction or inlet side of the latter.

at) Another of the said special objects is to eliminate water-hammer in the case of a rotary pump. Other objects are indicated in the course of the following portions of this specification.

An illustrative embodiment of the features of the invention is shown in the accompanying drawings, in which,

Fig. 1 is a central vertical section of my improved pump, made in the plane .of the however.

-Fig. 2 is a view in vertical section on line 2, 2, of Fig. 1.

Fig. 3 is an end elevation of the cylinder alone, and Fig. 4 is a vertical section on line 4:, 4:, of Fig. 3. v q

Fig. 5 is a side elevation, and Fig. 6 an end elevation, of one of the rotors.

Figs. 7 and 8 are, respectively, a side elevation of one of. the heads which close the ends of the cylinder. and an edge view thereof partly in vertical section.

Figs. 9, 10, and-11 are side, edge andtop views, respectively, of the casting for the partition by which the interior of the pump is divided into two chambers, such partition being shown in these views in one piece, as is the case prior to the casting being broken into sections to permit the assembling of the general organization.

Fi 12 is a view in section on line 12, 12, of Figf'l', showing one of the eq'uilibrizing ducts by which water-hammer is obviated.-

The general organization shown in the tilting a so-called cylinder, shown as a part driving shafts, the latter being in elevation,

drawings includes. a casing-body 1 consti of the general organization in Figs. 1 and l 2 and separately in Figs. 3 and 4, it having an internal chamber within which the rotors are located, and being provided with suction and discharge ports 21 and 22, respectively, which lead to and from, respectively, the

said chamber. Heads 2, 2, shown in placein the general organization in Fig. 1 and one thereof shown separately in Figs. 7

and 8, are secured to the opposite ends of the and 2, and which are described later herein.

In connection with the heads 2, 2*, bearings are provided for the shafts 5 and 6 (Figs.

and 2) of the two rotors, su h shafts being parallel with each other. End-portions of thesaid shafts project beyond one of the heads 2, 2, and have fixed thereon pinions 18, 19, Fig. 1, which intermesh with each other so as to provide for the transmission of motion from one rotor-shaft to the other to cause the two rotor-shafts and the rotors Some other form of hearing may be substi-.

tuted therefor if preferred. At 8, 8, Figs. 1

and 2, are non-rotating hubs in conjunction with the heads 2, 2, such hubs constitued in this instance by bushings or sleeves which are fixed in the heads 2, 2. The rotor-shafts 5 and 6 extend through these hubs, as shown,

and the respective hubs extend lengthwise of the said shafts from therespe tive heads 2, 2, along each of the respective shafts to near themiddle of the length of the casingbody or cylinder 1. In this instance the hubs are fitted to the rotor-shafts so as to serve as plain shaft-bearings, supplementing the roller-bearings 7, 7, and sustaining the shafts and the rotors at the places where the tendency to deflection of the shafts is greatest. If desired, the roller-bearings or the pre ferred substitute. therefor may be omitted, and the hubs 8, 8, alone may be depended upon as shaft-bearings, or, on the other the power will be transmitted from shaft 6 through connections suitable for the purose.

Upon each rotor-shaft is mounted a rotor. The drawings show in Figs. 1, 2, 5, 6, the preferred form of rotor. each rotor is constructed at mid-length there- .of with a hub 10 having a central hole or eye 11, Fig. 5, which fits the corres onding shaft, the said hub, in the assemble organization, being located upon the shaft at an intermediate point between the two cylinder heads 2, 2, and a key 12, Fig. l, which engages with the hub internally of the latter serving to provide for compelling rotation of the rotor with the shaft. In this instance, in accordance with one portion of theinvention, each rotor is provided with two sets of wings or impellers 13, 13, 14, 14, two of which 13,13) spaced apart angularly 180, as usua extend from the hub of the rotor toward one of the cylinder-heads 2, 2, while the other two thereof, (14, 14) similarly spaced apart angularly, extend from the hub inthe opposite direction toward the opposite cylinder-head 2. Thecylinder is divided interiorly into two lateral chambers by means of an intermediately located partition 16, which may be of figure-8 shape, as in Fig. 9, each aperture of which is occupied by the hub 10 of one rotor, so that the impellers extending in one direction at one side of the said partition occupy one of the said lateral chambers within the cylinder, while the impellers extending in the opposite direction at the opposite side of the partition occupy the cylin er. This provides two separate pumping units ,within the cylinder-casing. The two lateral chambers are both in communication with the suction port 21 and also are both in communication with the discharge port 22. It will be ercieved that the two sets of wings or impe lers 13, 13, and 14, 14,

' of each rotor are in staggered relationship,

the set extending in one direction within one lateral chamber being displaced angularly 90 with relation to the set extending in the o posite direction within the other lateral c amber, so that the respective wings or impellers of one set work out of phase with In this instance,

other lateral chamber within the:

those of the other set, i. e., alternate in action therewith, and thereby a continuous action in pumping, &c., is secured.

In efiect, the organization, as described thus far, provides a duplex structure resembling two pumps located side by side, each having its impeller wings or segments 13,13,01' 14, 14, as the case may be, disposed at an angular distance of 90 around from those of the other, and hence running out of phase with one another so as to give a balanced action at all speeds, with the loads equal and shared between both shafts alike. The same load conditions are manifest in the case of both the upper shaft 5 and the lower shaft 6. Each of such shafts takes 50% of the load continuously. Hence the improved organization is adapted to run at high speed with a minimum of vibration.

In practice, the partition 16 is produced through being cast in one integral. piece, as shown in Figs. 9, 10, 11, and machined while in that state. It is formed with weakened places in its top, middle, and bottom portions, for example by making holes 17, 17 17, insuch portions, and preparatory to assembling. it with other parts in the general organization its front and rear halves are broken apart at these places Or it might be cut through at the latter. The two symmetrical halves, after being separated from each other, may be fitted readily into place around the exteriors of the hubs of the tworotors in the process of assembling the parts of the organization.

The wall of the cylinder-chamber is shaped to provide oppositely-located semi-. circular interior concavities within which the rotors rotate,the interior surfaces of the corresponding portions of the said wall be- 105 ing concentric, respectively, with the respective shafts 5 and 6, and with the hubs 8, 8. The wings or impellers of the rotors travel a-roundwithin these concavities, between the convex exteriors of the sleeves and the con- 110 cave portions of the interior cylinder-wall.

. In accordance with one ortion of the invention, the wings or impe lers of the rotors are sector-shaped in cross-section, i. e., segmental, each thereof bein formed with a 115 concave inner side which ts the periphery of the hub 8 around which it rotates, and with a convex outer side which fits the concave surface of the adjacent concentric concave portion of the cylinder-wall.

It will be perceived on reference to Fig. 2 of the drawings that I provide for a con siderable width, circumferentially, of sliding surface contact between the concave in ner surface of a sector-shaped wing or im- 125 peller and the periphery ofv the correspondmg hub 8, and also between the covcx outer surface ofa wing or im eller and the adjacent concave portion 0 the cylinder-wall. This sliding surface contact provides eflec- 130 from the discharge side of a rotor to the suction side thereof,

With the same end in view, each hub 8 is formed with a peripheral concavity 15, Fig. 2, exigendin lengthwise of the hub and concentric with the other rotor-shaft, and the peripheries of the wings or impellers of. the rotor carried by the latter shaft successively enter this concavity and make sliding contact with the concave surface of the hub as the rotor rotates. This concavity provides for such an extent of surface contact, as contradistinguished from line-contact, between the convex outer surface of an impeller and the concave surface of the opposing hub, as

f wings on impellers, because of the ciated.

the impeller passes around, that leakage of fluid between an impeller and the hub, from the discharge side of the-rotors to the suction side, is reduced to a much smaller amount than if there were merely a linecontact between an impeller periphery and an opposing hub surface.

Heretotore, with pumps on the order of that shown herein the working speed has been restrioted,.and the rate of discharge has been kept below the theoretical maximum, because of the excessive development of water-hammer when a pump of such class is driven beyond a certain critical speed varying in different types. The said waterhammer produces noise, vibration, and \strain which occasionally breaks the joints ofthe piping with which the 'pump is asso- To keep down this action, the speed of the pump has had to be kept down. Such action in the case of pumps turning at high speed is due to the. creation of a partial vacuum in each of the advancing pumping pockets enclosed between v ocket the coacting a varich ving'been closed by b f b ers e ore ecoming ing 'wings or impe entirely filled with fluid. When the pocket is opened suddenly to the discharge port the high pressure of the fluid occupying such port creates back-flow into the pocket, with a noticeable shock. To avoid water hammer and render it practicable to run a pump at high speed, I provide as another feature of invention pressure-equilibrizing ducts 20, 20, Figs. 2, 3, l, in the inner surface of thewall of the cylinder, in working relation with the rotor-wings or impellers and the pockets intervenin between them. There are four of the said pressure-equih,

ibrizing ducts shown in Fi .4, namely two upper ones for securing t e desired pres- .sure equalizing actlon in connection with.

the pockets at right and left, res ectively, of the hub of the upper rotor in t e drawings, and two lower ones for securing such action in connection with the'corres' onding pockets of the lower rotor. These nets are formed'in this instance, as shown by Figs.

2. 3, 4, and 12, partly in the concave por- I tions of the inner surface of thenylinderwall andpartly in the straight portions of said wall alongside the discharge port. In the operation of the pump, the portion of a duct which extends into a concave portion of the wall is closed by the'convex peripheral portion of an advancing wing or impeller, so that the advancing ocket in the rear of such wing or irnpe ler is chamber until the heel of such wing or impeller pa'sses'the. beginning of the groove in the concave ortion-of the cylinder-wall. Thereupon leakage or backflow of fluid takes place from the discharge port, and through the equilibrizing duct into the succeeding pocket, until such pocket is completely occupied with fluid and the vacuum previously existing therein is filled. This avoids the action known as water-hammer, and" through eliminating the disadvantageous mm to be operated at a higher rate of speed than found practicable heretofore.

The rotors being symmetrical, the organization may be run in either direction as a pump, it desired, and by supplying fluid under pressure at one or the other port may also be run in either direction as a motor. To fit it for being run as a pump in a direction the reverse'of that indicated in the drawings, equilibrizing ducts should be made at each side of the rotors, instead of at one side only thereof as in the draw m s.

Tluid-pressure within the cylinder, due

sealed againstbackfiow from the d1scharge cuts thereof enables the pump lid as I

lOO

to the action of the rotors or otherwise reshafts may be prevented from reaching the provide means for intercepting.

bearings, such fluid and conducting it to the suctionchamber. lln the resent instancethe intercepting and con ucting means comprises peripheral grooves '51, 52, 53, and 61, 62, 63, formed in the respective shafts 5, 6, ex-

tending around the latter, and holes 81, 81,

in the hubs or sleeves 8, 8, extending radiallywithin the latter from theircentral openings to their peripheries, such holes opening into the chamber of the cylinder at the suction side of the rotors. Grooves and holes such as'just mentioned. are located intermediate the inner ends of the hubs orsleeves 8, 8, and the cylinder-heads, so that the means for intercepting and conducting to the suction-chamber is entirely internal of .the cylinder-casing. f

The grooves are shown herein in groups of three, there being one such group for each hub or sleeve, the innermost groove 51 or 61 of each group being separated somewhat from the remaining two, 52, 53, or 62,

63, which are closer together, constituting a pair. The neighboring hole 81 in the adjacent hub or sleeve registers with the said pair. As will be apparent, fluid passing outwardly along a rotor-shaft from the inner end of a hub or sleeve will collect or accumulate within the single groove, 51 or 61, from which it will work further outward along the shaftuntil it enters one or both of the pair of grooves, from which it will be withdrawn by suction into the suctionchamber, thus keeping it away from bearin s 7, 7. i

fiVhatis claimed as the invention is 1. An organization for the purposes described, comprising, essentially, a cylindercasing having opposite concave portions of cylindrical curvature, non-rotating cylindrical hubs in pairs, those of each pair concentric with the adjacent concave portion of the cylinderrcasing extending toward each other from opposite ends of the cylinder-casing and spaced apart at their proximate ends, rotor-shafts within said pairs of hubs, and impeller-hubs mounted on said rotor-shafts, projecting radially outward between said proximate ends, and provided with impellers extending axially of the" rotor-shafts in opposite directions, with the impellers of the respective rotor-shafts intcrmeshing in their rotation, and with the intermeshing sets that extend in one direction displaced angularly with relation to those extending in the opposite direction so as to produce alternating action whereby continuity and uniformity in the load upon the two rotor-shafts is maintained.

2. An organization for the purposes described, comprising, essentially, a cylindercasing, a rotor-shaft extending transversely with relation to the said cylinder-casing, a rotor carried by said rotor-shaft and working within said cylinder-casing, a shaftbearing in connection with said cylindercasing, and a sleeve-like hub extending from said cylinder-casing longitudinally .ofthe rotor-shaft and having means internal of the cylinder-casing for intercepting nonlubricatin'g fluid passing along the rotorshaft before such fluid reaches the bearing.

3. An organization for the purposes described, comprising, essentially, a cylindercasing, a rotor-shaft extending transversely with relation to the said cylinder-casing,- a rotor carried by said rotor-shaft and working within said? cylinder-casing, a shaftbearing in connection with said cylindercasing, and a sleeve-like hubextending from said 0 finder-casing longitudinally of the rotor comprising,

aft and having means internal of moaoee the cylinder-casing for intercepting nonlubricating fluid passing along the rotorshaft before such fluid reaches the bearing,

dividing the easing into two lateral cham bers, each of which is occupied by one of said sets of impeller members.

5. An organization of gear-pump type comprising, in combination, a casing, pa1red rotors therein each having sets of impeller members joined by an intermediate cylin drical hub, and extending in opposite directions from said hub and each other, and a partition fitting about the respective hubs and dividing the casing into two lateral chambers, each of which. is occupied by paired sets of impeller members.

6. An organization of gear-pump type in combination, a casing, a rotor therein having at each end a pair of impeller members, join ed by a cylindrical hub between the two pairs, the said pairs extending in opposite directions from the said hub and each other, and a partition fitting about the said hub dividing the easing into two chambers, through each of which fluid flows, the members of each pair being angularly displaced with respect to the members of the other pair to work out of phase with such other pair.

7. An organization of gear-pump type comprising, in combination, paired rotors therein each comprising an intermediate hub and pairs of impeller members extending in opposite directions from the said hub, and a partition fitting about the two hubs and dividing the easing into two chambets, through each of which fluid flows, with th; members of the pairswhich extend in one direction angularly displaced with respect to those of the pairs which extend in the opposite direction so as to work out of phase with the latter pairs.

8. In an organization of gear-pump type, the "combination with a cylinder having a rotor-compartment divided by a partition into lateral chambers, and a pair ofrotorshafts, of cylindrical members surrounding each of the respective shafts and extending from opposite ends of the cylinder toward "the said partition, and a pair of rotors comprising intermediately-located hubs by which the respective rotors are engaged with the respective rotor-shafts, said hubs occupying holes in the partition, and im-- 9. In an organization of gear-pump type,

. the combination with a cylinder having site directions rotor-compartments separated by an intervening partition, and a pair of rotor-shafts, of bushings extending from the ends of the cylinder toward the said partition and fitting the rotor-shafts, and a pair of rotors comprising intermediately-loc'ated hubs by which the respective rotors are mounted up on and engaged with the respective rotorshafts, and impellers which extend in oppofrom said hubs and the said partition and revolve in sliding contact with the peripheries ofthe said bushings.

10. An organization of gear-pump type comprising, in combination, a casing, a rotor therein having alternate impeller members and pockets for fluid, and a pressure-equalizing inlet adapted to permit access of the fluid at the discharge side into the advancing pumping pocket before the said pocket is opened at the discharge port.

11. An organization of gear-pump type comprisin the combination with a casing, and paire rotors therein having a plurality of impelling members thereon,

of a pressure-equalizing duct adapted to give access of the fiuid at the discharging side of the pump into the advancing pumping pocket before the said pocket is opened at the discharging point.

12. A. gear-pump comprising in combination a casing, and paired rotors therein provided with a plurality of fluid-impelling members with intervening pockets for fluid, and having means to admit gradually the fluid standing at the discharging side of the pump into a pocket between fluid-impelling members before such pocket is discharged.

13. A gear-pump comprising in combination a casing,fand paired rotors therein provided with a plurality of fluid-impelling members and intervening pockets for fluid, and having means to bring the fluid pressure within a pumping pocket between impeller members gradually to the same pressure as that of the fluid at the discharging side of the pump. 1 I

14. A gear-pump comprising the combination with a casing, and paired rotors therein provided with a plurality of fluidimpelling members, of means to bring the fluid pressure within a pumping pocket between such impelling members gradually to the same pressure as that of the fluid at the discharging side of the pump, before said pocket is opened at the discharging point. ALBERT L. FULLERTON. 

